The aim of this present study was to synthesize 2-substituted and 1,2-disubstituted benzimidazole derivatives to investigate their antibacterial diversity for possible future drug design. The structure-based design of precursors 2-(1H-benzimidazol-2-yl)aniline 1, 2-(3,5-dinitro phenyl)-1H-benzimidazole 3 and 2-benzyl-1H-benzimidazole 5 were achieved by the condensation reaction of o-phenylenediamine with anthranilic acid, 3,5-dinitrophenylbenzoic acid, and phenylacetic acid, respectively. The precursors 1, 3 and 5, upon reaction with six different electrophile-releasing agents, furnished the corresponding 2-substituted benzimidazole, 2a-f and 1,2-disubstituted benzimidazole derivatives 4a-f and 6a-f, respectively. The structural identity of the targeted compounds was authenticated by elemental analytical data and spectral information from FT-IR, UV, 1H, and 13C NMR. The outcome of the findings from the in vitro screening unveiled 2-benzyl-1-(phenylsulfonyl)-1H-benzimidazole 6b as the most active derivative with lowest MIC value of 15.63 µg/mL.

中文翻译：

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基于结构的功能化2-取代和1,2-二取代苯并咪唑衍生物的设计及其体外抗菌功效。

本研究的目的是合成 2-取代和 1,2-二取代的苯并咪唑衍生物，以研究它们的抗菌多样性，以用于未来可能的药物设计。通过缩合反应实现了前体 2-(1H-benzimidazol-2-yl)aniline 1、2-(3,5-dinitro phenyl)-1H-benzimidazole 3 和 2-benzyl-1H-benzimidazole 5 的结构设计。邻苯二胺分别与邻氨基苯甲酸、3,5-二硝基苯基苯甲酸和苯乙酸反应。前体 1、3 和 5 在与六种不同的亲电释放剂反应后，分别提供相应的 2-取代苯并咪唑、2a-f 和 1,2-二取代苯并咪唑衍生物 4a-f 和 6a-f。目标化合物的结构特征通过元素分析数据和 FT-IR 的光谱信息进行验证，紫外、1H 和 13C 核磁共振。体外筛选结果显示 2-苄基-1-(苯磺酰基)-1H-苯并咪唑 6b 是最活跃的衍生物，最低 MIC 值为 15.63 µg/mL。